   Unlike core pmap, it doesn't assume the buffer size is nprocessors + 2;
   instead, it tries to fill the pool."
   [pool f & colls]
-  (apply pmap-manual pool (impl/get-pool-size pool) f colls))
+  (apply pmap-manual pool nil f colls))
 
 (defn upmap-manual
   "Like pmap-manual, but with results returned in the order they completed.

                                      (with-meta #(apply f a)
                                                 {:args a}))))
         ;; force buffer-size futures to start work in the pool
         (forceahead buffer-size)
         ;; read the results from the futures
         (map deref)
         (pool-closer shutdown? pool))))

  background."
  [pool buffer-size f & colls]
  (let [[shutdown? pool] (impl/->threadpool pool)
        buffer-size (or buffer-size (impl/get-pool-size pool) 0)
        result-q (LinkedBlockingQueue. (int buffer-size))
        run-one (fn [a]
                  (let [p (promise)]
